CHEMICAL AND TOXICOLOGICAL CHARACTERIZATION OF AIRBORNE TOTAL SUSPENDED PARTICULATE (TSP) AND PM₁₀ ORGANIC EXTRACTS

Abstract

The relationship between chemical composition of airborne particulates and the genotoxicity has been investigated in the atmosphere of Rome, Italy. For this purpose, both total suspended particulate (TSP) and the PM ₁₀ fractions were collected daily inside a green park located in downtown, grouped on a weekly basis and speciated for their burdens of polycyclic aromatic hydrocarbons (PAH) and nitro-PAH. Concurrently, the genotoxicity of the organic extracts was evaluated by the Comet assay (SCGE: single cell gel electrophoresis) on human peripheral blood mononuclear cells (PBMC). The results indicate that organic extracts were able to induce DNA damage and a cytotoxic effect on PBMC. The TSP fraction was more cytotoxic than PM ₁₀ while the genotoxicity of both fractions was comparable. The genotoxic potential of the different samples was highly correlated to the amount of total PAH (correlation coefficient = 0.87), carcinogenic PAH (correlation coefficient = 0.88), B(a)P (correlation coefficient = 0.87) and to a less extend to the concentration of 1-nitropyrene (correlation coefficient = 0.66). The seasonal modulation suggests that in Rome the air is more toxic during winter, however in the warm season oxidized species including nitro-PAHs (evolving from secondary pollution) seem to balance the decrease of PAH concentration rates.

Keywords:

• Organic airborne particulates
• atmospheric pollution
• in-vitro bioassays
• genotoxicity
• gas chromatography –mass spectrometry

This paper is the synthesis of two poster communications (“Chemical Characterization of Airborne Total Suspended Particulate (TSP) and PM10 in Rome (Italy) Atmosphere” and “Biological Effects Induced in vitro by Organic Extracts of Airborne Total Suspended Particulate (TSP) and PM₁₀” presented at the 21st ISPAC Symposium, Trondheim (Norway), August 5–10, 2007.

Notes

^a“total PAH” is the sum of all congeners speciated including also the methyl-substituted ones;

^bfor BaPY-equivalent power (BaPE) see the text;

^c“carcinogenic PAH” is the sum of concentrations of the seven congeners recognized as carcinogens (BaPE formula).